import React, { Component } from 'react';


class Clock extends Component {
  constructor(props) {
    super(props);
    this.state = {date: new Date()};
  }

  componentDidMount() {
    this.timerID = setInterval(
      () => this.tick(),
      1000
    );
  }

  componentWillUnmount() {
    clearInterval(this.timerID)
  }

  tick() {
    this.setState({
      date: new Date()
    })
  }

  render() {
    return (
      <div >
        <h1>Hello, World</h1>
        <h2> It is {this.state.date.toLocaleTimeString()}</h2>
        
      </div>
    );
  }
}

export default Clock;
